I don't see this as an issue in play, especially if you are a fighter as you get a bunch of weapon masteries and at level 9 the ability to use ones other than the one for that weapon. More often than not I have more masteries than I have weapons when playing a fighter.
The limited number can be an issue for a Rogue, Ranger or Paladin, but I think that is part of making the Fighter and Barbarian unique.
The feat is very weak, but it is worth considering for a Bladelock, Valor Bard or Bladesinger and if you are not going to take the feat you really should consider multiclassing for mastery.